Jim Parsons and Mayim Bialik's characters, Sheldon and Amy, will finally go all the way on Thursday's episode of "The Big Bang Theory" after many years of dating. Here's a look at who's who in the cast.
Jim Parsons has won four Emmys for his portrayal of physicist Sheldon Cooper, who is as clueless about social interaction as he is knowledgeable about science.
Simon Helberg plays Howard Wolowitz, an aerospace engineer who started out a bit awkward with women but these days is happily married.
"Roseanne" alum Johnny Galecki stars as Leonard Hofstadter, Sheldon's long-suffering roommate and the love interest of Penny (Kaley Cuoco). He is a physicist.
Cuoco, left, plays Penny, a waitress who can't quite match wits with her group of friends but nevertheless hangs out with them.
Rauch's Bernadette Rostenkowski-Wolowitz is a highly paid scientist who is married to Howard. A frequent joke in the show is how she can be as overbearing as his mother.
Three-time Emmy nominee Mayim Bialik plays Amy Farrah Fowler, a scientist who is involved with Sheldon. She also believes she is best friends with Penny.
Kunal Nayyar plays Rajesh Ramayan "Raj" Koothrappali, a shy astrophysicist who up until recently could talk to women only after he drank alcohol. He is desperate to find true love and recently, finally found a girlfriend.